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Pasternak Y, Vong L, Merico D, Abrego Fuentes L, Scott O, Sham M, Fraser M, Watts-Dickens A, Willett Pachul J, Kim VH, Marshall CR, Scherer S, Roifman CM. Utilization of next-generation sequencing to define the role of heterozygous FOXN1 variants in immunodeficiency. THE JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY. GLOBAL 2024; 3:100267. [PMID: 38800615 PMCID: PMC11127205 DOI: 10.1016/j.jacig.2024.100267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 01/26/2024] [Accepted: 02/03/2024] [Indexed: 05/29/2024]
Abstract
Background Forkhead box protein N1 (FOXN1) transcription factor plays an essential role in the development of thymic epithelial cells, required for T-cell differentiation, maturation, and function. Biallelic pathogenic variants in FOXN1 cause severe combined immunodeficiency (SCID). More recently, heterozygous variants in FOXN1, identified by restricted gene panels, were also implicated with causing a less severe and variable immunodeficiency. Objective We undertook longitudinal follow-up and advanced genetic investigations, including whole exome sequencing and whole genome sequencing, of newborns with a heterozygous variant in FOXN1. Methods Five patients (3 female, 2 male) have been followed since they were first detected with low T-cell receptor excision circles during newborn screening for SCID. Patients underwent immune evaluation as well as genetic testing, including a primary immunodeficiency panel, whole exome sequencing, and whole genome sequencing in some cases. Results Median follow-up time was 6.5 years. Initial investigations revealed low CD3+ T lymphocytes in all patients. One patient presented with extremely low lymphocyte counts and depressed phytohemagglutinin responses leading to a tentative diagnosis of SCID. Over a period of 2 years, CD3+ T-cell counts rose, although in some patients it remained borderline low. One of 5 children continues to experience recurrent upper respiratory infections and asthma episodes. The remaining are asymptomatic except for eczema in 2 of 5 cases. Lymphocyte proliferation responses to phytohemagglutinin were initially low in 3 patients but normalized by age 10 months. In 3 of 5 cases, T lymphocyte counts remain low/borderline low. Conclusion In cases of monoallelic FOXN1 variants, using whole exome sequencing and whole genome sequencing to rule out possible other significant pathogenic variants allowed us to proceed with confidence in a conservative manner, even in extreme cases consistent with newborn screen-positive early presentation of SCID.
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Affiliation(s)
- Yehonatan Pasternak
- Division of Immunology and Allergy, Department of Paediatrics, The Hospital for Sick Children and the University of Toronto, Toronto, Ontario, Canada
| | - Linda Vong
- Division of Immunology and Allergy, Department of Paediatrics, The Hospital for Sick Children and the University of Toronto, Toronto, Ontario, Canada
- Canadian Centre for Primary Immunodeficiency and the Jeffrey Modell Research Laboratory for the Diagnosis of Primary Immunodeficiency, The Hospital for Sick Children and Research Institute, Toronto, Ontario, Canada
| | - Daniele Merico
- Vevo Therapeutics, San Francisco, Calif
- The Centre for Applied Genomics (TCAG), Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Laura Abrego Fuentes
- Division of Immunology and Allergy, Department of Paediatrics, The Hospital for Sick Children and the University of Toronto, Toronto, Ontario, Canada
| | - Ori Scott
- Division of Immunology and Allergy, Department of Paediatrics, The Hospital for Sick Children and the University of Toronto, Toronto, Ontario, Canada
| | - Marina Sham
- Division of Immunology and Allergy, Department of Paediatrics, The Hospital for Sick Children and the University of Toronto, Toronto, Ontario, Canada
| | - Meghan Fraser
- Newborn Screening Program, Department of Clinical and Metabolic Genetics, The Hospital for Sick Children and the University of Toronto, Toronto, Ontario, Canada
| | - Abby Watts-Dickens
- Newborn Screening Program, Department of Clinical and Metabolic Genetics, The Hospital for Sick Children and the University of Toronto, Toronto, Ontario, Canada
- Department of Molecular Genetics and the McLaughlin Centre, University of Toronto, Toronto, Ontario, Canada
| | - Jessica Willett Pachul
- Division of Immunology and Allergy, Department of Paediatrics, The Hospital for Sick Children and the University of Toronto, Toronto, Ontario, Canada
| | - Vy H.D. Kim
- Division of Immunology and Allergy, Department of Paediatrics, The Hospital for Sick Children and the University of Toronto, Toronto, Ontario, Canada
| | - Christian R. Marshall
- Division of Genome Diagnostics, Department of Paediatric Laboratory Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Stephen Scherer
- The Centre for Applied Genomics (TCAG), Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Molecular Genetics and the McLaughlin Centre, University of Toronto, Toronto, Ontario, Canada
| | - Chaim M. Roifman
- Division of Immunology and Allergy, Department of Paediatrics, The Hospital for Sick Children and the University of Toronto, Toronto, Ontario, Canada
- Canadian Centre for Primary Immunodeficiency and the Jeffrey Modell Research Laboratory for the Diagnosis of Primary Immunodeficiency, The Hospital for Sick Children and Research Institute, Toronto, Ontario, Canada
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2
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Howley E, Soomann M, Kreins AY. Parental Engagement in Identifying Information Needs After Newborn Screening for Families of Infants with Suspected Athymia. J Clin Immunol 2024; 44:79. [PMID: 38457046 PMCID: PMC10923976 DOI: 10.1007/s10875-024-01678-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Accepted: 02/26/2024] [Indexed: 03/09/2024]
Abstract
Congenital athymia is a rare T-lymphocytopaenic condition, which requires early corrective treatment with thymus transplantation (TT). Athymic patients are increasingly identified through newborn screening (NBS) for severe combined immunodeficiency (SCID). Lack of relatable information resources contributes to challenging patient and family journeys during the diagnostic period following abnormal NBS results. Patient and Public Involvement and Engagement (PPIE) activities, including parental involvement in paediatrics, are valuable initiatives to improve clinical communication and parental information strategies. Parents of infants with suspected athymia were therefore invited to discuss the information they received during the diagnostic period following NBS with the aim to identify parental information needs and targeted strategies to address these adequately. Parents reported that athymia was not considered with them as a possible differential diagnosis until weeks after initial NBS results. Whilst appropriate clinical information about athymia and TT was available upon referral to specialist immunology services, improved access to easy-to-understand information from reliable sources, including from clinical nurse specialists and peer support systems, remained desirable. A roadmap concept, with written or digital information, addressing parental needs in real time during a potentially complex diagnostic journey, was proposed and is transferrable to other inborn errors of immunity (IEI) and rare diseases. This PPIE activity provides insight into the information needs of parents of infants with suspected athymia who are identified through SCID NBS, and highlights the role for PPIE in promoting patient- and family-centred strategies to improve IEI care.
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Affiliation(s)
- Evey Howley
- Department of Immunology and Gene Therapy, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Maarja Soomann
- Department of Immunology and Gene Therapy, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
- Division of Immunology and the Children's Research Centre, University Children's Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Alexandra Y Kreins
- Department of Immunology and Gene Therapy, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK.
- Infection Immunity and Inflammation Research and Teaching Department, University College London Great Ormond Street Institute of Child Health, London, UK.
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3
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Dinges SS, Amini K, Notarangelo LD, Delmonte OM. Primary and secondary defects of the thymus. Immunol Rev 2024; 322:178-211. [PMID: 38228406 PMCID: PMC10950553 DOI: 10.1111/imr.13306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2024]
Abstract
The thymus is the primary site of T-cell development, enabling generation, and selection of a diverse repertoire of T cells that recognize non-self, whilst remaining tolerant to self- antigens. Severe congenital disorders of thymic development (athymia) can be fatal if left untreated due to infections, and thymic tissue implantation is the only cure. While newborn screening for severe combined immune deficiency has allowed improved detection at birth of congenital athymia, thymic disorders acquired later in life are still underrecognized and assessing the quality of thymic function in such conditions remains a challenge. The thymus is sensitive to injury elicited from a variety of endogenous and exogenous factors, and its self-renewal capacity decreases with age. Secondary and age-related forms of thymic dysfunction may lead to an increased risk of infections, malignancy, and autoimmunity. Promising results have been obtained in preclinical models and clinical trials upon administration of soluble factors promoting thymic regeneration, but to date no therapy is approved for clinical use. In this review we provide a background on thymus development, function, and age-related involution. We discuss disease mechanisms, diagnostic, and therapeutic approaches for primary and secondary thymic defects.
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Affiliation(s)
- Sarah S. Dinges
- Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
- Department of Pediatric Respiratory Medicine, Immunology and Critical Care Medicine, Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Kayla Amini
- Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Luigi D. Notarangelo
- Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ottavia M. Delmonte
- Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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4
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Moses A, Bhalla P, Thompson A, Lai L, Coskun FS, Seroogy CM, de la Morena MT, Wysocki CA, van Oers NSC. Comprehensive phenotypic analysis of diverse FOXN1 variants. J Allergy Clin Immunol 2023; 152:1273-1291.e15. [PMID: 37419334 PMCID: PMC11071152 DOI: 10.1016/j.jaci.2023.06.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 05/05/2023] [Accepted: 06/08/2023] [Indexed: 07/09/2023]
Abstract
BACKGROUND Thymus hypoplasia due to stromal cell problems has been linked to mutations in several transcription factors, including Forkhead box N1 (FOXN1). FOXN1 supports T-cell development by regulating the formation and expansion of thymic epithelial cells (TECs). While autosomal recessive FOXN1 mutations result in a nude and severe combined immunodeficiency phenotype, the impact of single-allelic or compound heterozygous FOXN1 mutations is less well-defined. OBJECTIVE With more than 400 FOXN1 mutations reported, their impact on protein function and thymopoiesis remains unclear for most variants. We developed a systematic approach to delineate the functional impact of diverse FOXN1 variants. METHODS Selected FOXN1 variants were tested with transcriptional reporter assays and imaging studies. Thymopoiesis was assessed in mouse lines genocopying several human FOXN1 variants. Reaggregate thymus organ cultures were used to compare the thymopoietic potential of the FOXN1 variants. RESULTS FOXN1 variants were categorized into benign, loss- or gain-of-function, and/or dominant-negatives. Dominant negative activities mapped to frameshift variants impacting the transactivation domain. A nuclear localization signal was mapped within the DNA binding domain. Thymopoiesis analyses with mouse models and reaggregate thymus organ cultures revealed distinct consequences of particular Foxn1 variants on T-cell development. CONCLUSIONS The potential effect of a FOXN1 variant on T-cell output from the thymus may relate to its effects on transcriptional activity, nuclear localization, and/or dominant negative functions. A combination of functional assays and thymopoiesis comparisons enabled a categorization of diverse FOXN1 variants and their potential impact on T-cell output from the thymus.
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Affiliation(s)
- Angela Moses
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, Tex
| | - Pratibha Bhalla
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, Tex
| | - Austin Thompson
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, Tex
| | - Laijun Lai
- Department of Allied Health Sciences, University of Connecticut, Storrs, Conn
| | - Fatma S Coskun
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, Tex
| | - Christine M Seroogy
- the Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, Wis
| | - Maria Teresa de la Morena
- the Department of Pediatrics, University of Washington and Seattle Children's Hospital, Seattle, Wash
| | - Christian A Wysocki
- Departments of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Tex; Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Tex
| | - Nicolai S C van Oers
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, Tex; Departments of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Tex; Microbiology, University of Texas Southwestern Medical Center, Dallas, Tex.
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5
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Kearns NA, Lobo M, Genga RMJ, Abramowitz RG, Parsi KM, Min J, Kernfeld EM, Huey JD, Kady J, Hennessy E, Brehm MA, Ziller MJ, Maehr R. Generation and molecular characterization of human pluripotent stem cell-derived pharyngeal foregut endoderm. Dev Cell 2023; 58:1801-1818.e15. [PMID: 37751684 PMCID: PMC10637111 DOI: 10.1016/j.devcel.2023.08.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Revised: 05/15/2023] [Accepted: 08/18/2023] [Indexed: 09/28/2023]
Abstract
Approaches to study human pharyngeal foregut endoderm-a developmental intermediate that is linked to various human syndromes involving pharynx development and organogenesis of tissues such as thymus, parathyroid, and thyroid-have been hampered by scarcity of tissue access and cellular models. We present an efficient stepwise differentiation method to generate human pharyngeal foregut endoderm from pluripotent stem cells. We determine dose and temporal requirements of signaling pathway engagement for optimized differentiation and characterize the differentiation products on cellular and integrated molecular level. We present a computational classification tool, "CellMatch," and transcriptomic classification of differentiation products on an integrated mouse scRNA-seq developmental roadmap confirms cellular maturation. Integrated transcriptomic and chromatin analyses infer differentiation stage-specific gene regulatory networks. Our work provides the method and integrated multiomic resource for the investigation of disease-relevant loci and gene regulatory networks and their role in developmental defects affecting the pharyngeal endoderm and its derivatives.
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Affiliation(s)
- Nicola A Kearns
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA; Diabetes Center of Excellence, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Macrina Lobo
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA; Diabetes Center of Excellence, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Ryan M J Genga
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA; Diabetes Center of Excellence, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Ryan G Abramowitz
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA; Diabetes Center of Excellence, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Krishna M Parsi
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA; Diabetes Center of Excellence, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Jiang Min
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA; Diabetes Center of Excellence, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Eric M Kernfeld
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA; Diabetes Center of Excellence, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Jack D Huey
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA; Diabetes Center of Excellence, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Jamie Kady
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA; Diabetes Center of Excellence, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Erica Hennessy
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA; Diabetes Center of Excellence, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Michael A Brehm
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA; Diabetes Center of Excellence, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Michael J Ziller
- Department of Psychiatry, University of Münster, Münster, Germany
| | - René Maehr
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA; Diabetes Center of Excellence, University of Massachusetts Chan Medical School, Worcester, MA, USA.
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6
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Bosticardo M, Notarangelo LD. Human thymus in health and disease: Recent advances in diagnosis and biology. Semin Immunol 2023; 66:101732. [PMID: 36863139 PMCID: PMC10134747 DOI: 10.1016/j.smim.2023.101732] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 01/30/2023] [Accepted: 02/14/2023] [Indexed: 03/04/2023]
Abstract
The thymus is the crucial tissue where thymocytes develop from hematopoietic precursors that originate from the bone marrow and differentiate to generate a repertoire of mature T cells able to respond to foreign antigens while remaining tolerant to self-antigens. Until recently, most of the knowledge on thymus biology and its cellular and molecular complexity have been obtained through studies in animal models, because of the difficulty to gain access to thymic tissue in humans and the lack of in vitro models able to faithfully recapitulate the thymic microenvironment. This review focuses on recent advances in the understanding of human thymus biology in health and disease obtained through the use of innovative experimental techniques (eg. single cell RNA sequencing, scRNAseq), diagnostic tools (eg. next generation sequencing), and in vitro models of T-cell differentiation (artificial thymic organoids) and thymus development (eg. thymic epithelial cell differentiation from embryonic stem cells or induced pluripotent stem cells).
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Affiliation(s)
- Marita Bosticardo
- Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
| | - Luigi D Notarangelo
- Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
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7
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Dvorak CC, Haddad E, Heimall J, Dunn E, Buckley RH, Kohn DB, Cowan MJ, Pai SY, Griffith LM, Cuvelier GDE, Eissa H, Shah AJ, O'Reilly RJ, Pulsipher MA, Wright NAM, Abraham RS, Satter LF, Notarangelo LD, Puck JM. The diagnosis of severe combined immunodeficiency (SCID): The Primary Immune Deficiency Treatment Consortium (PIDTC) 2022 Definitions. J Allergy Clin Immunol 2023; 151:539-546. [PMID: 36456361 PMCID: PMC9905311 DOI: 10.1016/j.jaci.2022.10.022] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 10/18/2022] [Accepted: 10/21/2022] [Indexed: 11/29/2022]
Abstract
Severe combined immunodeficiency (SCID) results from defects in the differentiation of hematopoietic stem cells into mature T lymphocytes, with additional lymphoid lineages affected in particular genotypes. In 2014, the Primary Immune Deficiency Treatment Consortium published criteria for diagnosing SCID, which are now revised to incorporate contemporary approaches. Patients with typical SCID must have less than 0.05 × 109 autologous T cells/L on repetitive testing, with either pathogenic variant(s) in a SCID-associated gene, very low/undetectable T-cell receptor excision circles or less than 20% of CD4 T cells expressing naive markers, and/or transplacental maternally engrafted T cells. Patients with less profoundly impaired autologous T-cell differentiation are designated as having leaky/atypical SCID, with 2 or more of these: low T-cell numbers, oligoclonal T cells, low T-cell receptor excision circles, and less than 20% of CD4 T cells expressing naive markers. These patients must also have either pathogenic variant(s) in a SCID-associated gene or reduced T-cell proliferation to certain mitogens. Omenn syndrome requires a generalized erythematous rash, absent transplacentally acquired maternal engraftment, and 2 or more of these: eosinophilia, elevated IgE, lymphadenopathy, hepatosplenomegaly. Thymic stromal defects and other causes of secondary T-cell deficiency are excluded from the definition of SCID. Application of these revised Primary Immune Deficiency Treatment Consortium 2022 Definitions permits precise categorization of patients with T-cell defects but does not imply a preferred treatment strategy.
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Affiliation(s)
- Christopher C Dvorak
- Division of Pediatric Allergy, Immunology, and Bone Marrow Transplantation, University of California San Francisco, San Francisco, Calif.
| | - Elie Haddad
- Department of Pediatrics, University of Montreal, CHU Sainte-Justine, Montreal, Quebec, Canada
| | - Jennifer Heimall
- Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, and Division of Allergy and Immunology, Children's Hospital of Philadelphia, Philadelphia, Pa
| | - Elizabeth Dunn
- Division of Pediatric Allergy, Immunology, and Bone Marrow Transplantation, University of California San Francisco, San Francisco, Calif
| | - Rebecca H Buckley
- Division of Pediatric Allergy and Immunology, Duke University Medical Center, Durham, NC
| | - Donald B Kohn
- Department of Microbiology, Immunology & Molecular Genetics, University of California, Los Angeles, Los Angeles, Calif; Department of Pediatrics, University of California, Los Angeles, Los Angeles, Calif
| | - Morton J Cowan
- Division of Pediatric Allergy, Immunology, and Bone Marrow Transplantation, University of California San Francisco, San Francisco, Calif
| | - Sung-Yun Pai
- Immune Deficiency Cellular Therapy Program, Center for Cancer Research, National Cancer Institute, Bethesda, Md
| | - Linda M Griffith
- Division of Allergy Immunology and Transplantation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Md
| | - Geoffrey D E Cuvelier
- Manitoba Blood and Marrow Transplant Program, CancerCare Manitoba, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Hesham Eissa
- Division of Pediatric Hematology-Oncology-BMT, University of Colorado, Aurora, Colo
| | - Ami J Shah
- Division of Pediatric Hematology, Oncology, Stem Cell Transplantation and Regenerative Medicine, Stanford School of Medicine, Palo Alto, Calif
| | - Richard J O'Reilly
- Department of Pediatrics, Stem Cell Transplantation and Cellular Therapies Service, Memorial Sloan Kettering, New York, NY
| | - Michael A Pulsipher
- Division of Pediatric Hematology and Oncology, Intermountain Primary Childrens Hospital, Huntsman Cancer Institute at the University of Utah, Salt Lake City, Utah
| | - Nicola A M Wright
- Department of Pediatrics, Alberta Children's Hospital, University of Calgary, Calgary, Alberta, Canada
| | - Roshini S Abraham
- Department of Pathology and Laboratory Medicine, Nationwide Children's Hospital and The Ohio State University College of Medicine, Columbus, Ohio
| | - Lisa Forbes Satter
- Pediatric Immunology Allergy and Retrovirology, Baylor College of Medicine, Houston, Tex
| | - Luigi D Notarangelo
- Division of Allergy Immunology and Transplantation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Md
| | - Jennifer M Puck
- Division of Pediatric Allergy, Immunology, and Bone Marrow Transplantation, University of California San Francisco, San Francisco, Calif
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8
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Ghosh R, Bosticardo M, Singh S, Similuk M, Delmonte OM, Pala F, Peng C, Jodarski C, Keller MD, Chinn IK, Groves AK, Notarangelo LD, Walkiewicz MA, Chinen J, Bundy V. FOXI3 haploinsufficiency contributes to low T-cell receptor excision circles and T-cell lymphopenia. J Allergy Clin Immunol 2022; 150:1556-1562. [PMID: 35987349 PMCID: PMC9742176 DOI: 10.1016/j.jaci.2022.08.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 08/11/2022] [Accepted: 08/15/2022] [Indexed: 12/14/2022]
Abstract
BACKGROUND Newborn screening can identify neonatal T-cell lymphopenia through detection of a low number of copies of T-cell receptor excision circles in dried blood spots collected at birth. After a positive screening result, further diagnostic testing is required to determine whether the subject has severe combined immunodeficiency or other causes of T-cell lymphopenia. Even after thorough evaluation, approximately 15% of children with a positive result of newborn screening for T-cell receptor excision circles remain genetically undiagnosed. Identifying the underlying genetic etiology is necessary to guide subsequent clinical management and family planning. OBJECTIVE We sought to elucidate the genetic basis of patients with T-cell lymphopenia without an apparent genetic diagnosis. METHODS We used clinical genomic testing as well as functional and immunologic assays to identify and elucidate the genetic and mechanistic basis of T-cell lymphopenia. RESULTS We report 2 unrelated individuals with nonsevere T-cell lymphopenia and abnormal T-cell receptor excision circles who harbor heterozygous loss-of-function variants in forkhead box I3 transcription factor (FOXI3). CONCLUSION Our findings support the notion that haploinsufficiency of FOXI3 results in T-cell lymphopenia with variable expressivity and that FOXI3 may be a key modulator of thymus development.
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Affiliation(s)
- Rajarshi Ghosh
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Md
| | - Marita Bosticardo
- Laboratory of Clinical Immunology and Microbiology, Division of Intramural Research, National Institutes of Health, Bethesda, Md
| | - Sunita Singh
- Department of Neuroscience, Baylor College of Medicine, Houston, Tex
| | - Morgan Similuk
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Md
| | - Ottavia M Delmonte
- Laboratory of Clinical Immunology and Microbiology, Division of Intramural Research, National Institutes of Health, Bethesda, Md
| | - Francesca Pala
- Laboratory of Clinical Immunology and Microbiology, Division of Intramural Research, National Institutes of Health, Bethesda, Md
| | - Christine Peng
- Division of Allergy and Immunology, Children's National Hospital, Washington, DC
| | - Colleen Jodarski
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Md
| | - Michael D Keller
- Division of Allergy and Immunology, Children's National Hospital, Washington, DC
| | - Ivan K Chinn
- Division of Immunology, Allergy, and Retrovirology, Department of Pediatrics, Baylor College of Medicine, Houston, Tex
| | - Andrew K Groves
- Department of Neuroscience, Baylor College of Medicine, Houston, Tex; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Tex
| | - Luigi D Notarangelo
- Laboratory of Clinical Immunology and Microbiology, Division of Intramural Research, National Institutes of Health, Bethesda, Md.
| | - Magdalena A Walkiewicz
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Md.
| | - Javier Chinen
- Division of Immunology, Allergy, and Retrovirology, Department of Pediatrics, Baylor College of Medicine, Houston, Tex; Texas Children's Hospital, The Woodlands, Tex.
| | - Vanessa Bundy
- Clinical Development, Immunology, Janssen Research and Development, Spring House, Pa.
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9
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Muacevic A, Adler JR. FOXN1 Gene Considerations in Severe Combined Immunodeficiency Treatment in Children. Cureus 2022; 14:e32040. [PMID: 36600823 PMCID: PMC9800850 DOI: 10.7759/cureus.32040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/29/2022] [Indexed: 12/05/2022] Open
Abstract
Forkheadbox N1 (FOXN1) gene mutation in humans is a rare cause of thymic hypoplasia and T cell immunodeficiency. This gene is the master transcriptional regulator of thymic epithelial cells and disruptions have been described in consequence to a variety of antepartum complications. FOXN1 mutation-mediated immune deficiency is typically associated with severe combined immunodeficiency and alopecia universalis (SCID/NUDE phenotypes) with homozygous alterations in human animal models. Less common, however, FOXN1 alterations can occur in a heterozygous form and provide a distinct phenotype of severe combined immunodeficiency (SCID) without alopecia. Here, we present one such case of a Caucasian child born with heterozygous FOXN1 mutation, first presenting with undetectable T cell levels at newborn screen. He was confirmed to have FOXN1 immunodeficiency in the heterozygous form through genetic testing. Early identification and initiation of appropriate interventions are crucial to reduce mortality from opportunistic pathogens associated with immunodeficiency. Furthermore, we need to appreciate the less common presentations of established diseases among young patients.
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10
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Nagakubo D, Hirakawa M, Iwanami N, Boehm T. Limits to in vivo fate changes of epithelia in thymus and parathyroid by ectopic expression of transcription factors Gcm2 and Foxn1. Sci Rep 2022; 12:13554. [PMID: 35941210 PMCID: PMC9360016 DOI: 10.1038/s41598-022-17844-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 08/02/2022] [Indexed: 11/09/2022] Open
Abstract
The development of the parathyroid and the thymus from the third pharyngeal pouch depends on the activities of the Gcm2 and Foxn1 transcription factors, respectively, whose expression domains sharply demarcate two regions in the developing third pharyngeal pouch. Here, we have generated novel mouse models to examine whether ectopic co-expression of Gcm2 in the thymic epithelium and of Foxn1 in the parathyroid perturbs the establishment of organ fates in vivo. Expression of Gcm2 in the thymic rudiment does not activate a parathyroid-specific expression programme, even in the absence of Foxn1 activity. Co-expression of Foxn1 in the parathyroid fails to impose thymopoietic capacity. We conclude that the actions of Foxn1 and Gcm2 transcription factors are cell context-dependent and that they each require permissive transcription factor landscapes in order to successfully interfere with organ-specific cell fate.
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Affiliation(s)
- Daisuke Nagakubo
- Department of Developmental Immunology, Max Planck Institute of Immunobiology and Epigenetics, Stuebeweg 51, 79108, Freiburg, Germany.,Division of Health and Hygienic Sciences, Faculty of Pharmaceutical Sciences, Himeji Dokkyo University, 7-2-1 Kamiohno, Himeji, Hyogo, 670-8524, Japan
| | - Mayumi Hirakawa
- Department of Developmental Immunology, Max Planck Institute of Immunobiology and Epigenetics, Stuebeweg 51, 79108, Freiburg, Germany.,Division of Immunology and Allergy, Research Institute for Biomedical Sciences, Tokyo University of Science, 2669 Yamazaki, Noda-City, Chiba, 278-0022, Japan
| | - Norimasa Iwanami
- Department of Developmental Immunology, Max Planck Institute of Immunobiology and Epigenetics, Stuebeweg 51, 79108, Freiburg, Germany.,Center for Bioscience Research and Education, Utsunomiya University, Utsunomiya, Tochigi, 321-8505, Japan
| | - Thomas Boehm
- Department of Developmental Immunology, Max Planck Institute of Immunobiology and Epigenetics, Stuebeweg 51, 79108, Freiburg, Germany.
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11
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Urschel D, Hernandez-Trujillo VP. Spectrum of Genetic T-Cell Disorders from 22q11.2DS to CHARGE. Clin Rev Allergy Immunol 2022; 63:99-105. [PMID: 35133619 DOI: 10.1007/s12016-022-08927-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/13/2022] [Indexed: 01/12/2023]
Abstract
Improved genetic testing has led to recognition of a diverse group of disorders of inborn errors of immunity that present as primarily T-cell defects. These disorders present with variable degrees of immunodeficiency, autoimmunity, multiple organ system dysfunction, and neurocognitive defects. 22q11.2 deletion syndrome, commonly known as DiGeorge syndrome, represents the most common disorder on this spectrum. In most individuals, a 3 Mb deletion of 22q11 results in haploinsufficiency of 90 known genes and clinical complications of varying severity. These include cardiac, endocrine, gastrointestinal, renal, palatal, genitourinary, and neurocognitive anomalies. Multidisciplinary treatment also includes pediatrics/general practitioners, genetic counseling, surgery, interventional therapy, and psychology/psychiatry. Chromosome 10p deletion, TBX1 mutation, CHD7 mutation, Jacobsen syndrome, and FOXN1 deficiency manifest with similar overlapping clinical presentations and T-cell defects. Recognition of the underlying disorder and pathogenesis is essential for improved outcomes. Diagnosing and treating these heterogenous conditions are a challenge and rapidly improving with new diagnostic tools. Collectively, these disorders are an example of the complex penetrance and severity of genetic disorders, importance of translational diagnostics, and a guide for multidisciplinary treatment.
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Affiliation(s)
- Daniel Urschel
- Department of Medical Education, Nicklaus Children's Hospital, Miami, FL, USA. .,Division of Allergy and Immunology, Nicklaus Children's Hospital, Miami, FL, USA. .,Allergy and Immunology Care Center of South Florida, Miami Lakes, FL, USA.
| | - Vivian P Hernandez-Trujillo
- Department of Medical Education, Nicklaus Children's Hospital, Miami, FL, USA.,Division of Allergy and Immunology, Nicklaus Children's Hospital, Miami, FL, USA.,Allergy and Immunology Care Center of South Florida, Miami Lakes, FL, USA
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12
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Pala F, Notarangelo LD, Bosticardo M. Inborn errors of immunity associated with defects of thymic development. Pediatr Allergy Immunol 2022; 33:e13832. [PMID: 36003043 PMCID: PMC11077434 DOI: 10.1111/pai.13832] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 06/29/2022] [Accepted: 07/07/2022] [Indexed: 12/18/2022]
Abstract
The main function of the thymus is to support the establishment of a wide repertoire of T lymphocytes capable of eliminating foreign pathogens, yet tolerant to self-antigens. Thymocyte development in the thymus is dependent on the interaction with thymic stromal cells, a complex mixture of cells comprising thymic epithelial cells (TEC), mesenchymal and endothelial cells. The exchange of signals between stromal cells and thymocytes is referred to as "thymic cross-talk". Genetic defects affecting either side of this interaction result in defects in thymic development that ultimately lead to a decreased output of T lymphocytes to the periphery. In the present review, we aim at providing a summary of inborn errors of immunity (IEI) characterized by T-cell lymphopenia due to defects of the thymic stroma, or to hematopoietic-intrinsic defects of T-cell development, with a special focus on recently discovered disorders. Additionally, we review the novel diagnostic tools developed to discover and study new genetic causes of IEI due to defects in thymic development. Finally, we discuss therapeutic approaches to correct thymic defects that are currently available, in addition to potential novel therapies that could be applied in the future.
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Affiliation(s)
- Francesca Pala
- Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Luigi D Notarangelo
- Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Marita Bosticardo
- Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
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13
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Bhalla P, Su DM, van Oers NSC. Thymus Functionality Needs More Than a Few TECs. Front Immunol 2022; 13:864777. [PMID: 35757725 PMCID: PMC9229346 DOI: 10.3389/fimmu.2022.864777] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 05/03/2022] [Indexed: 12/18/2022] Open
Abstract
The thymus, a primary lymphoid organ, produces the T cells of the immune system. Originating from the 3rd pharyngeal pouch during embryogenesis, this organ functions throughout life. Yet, thymopoiesis can be transiently or permanently damaged contingent on the types of systemic stresses encountered. The thymus also undergoes a functional decline during aging, resulting in a progressive reduction in naïve T cell output. This atrophy is evidenced by a deteriorating thymic microenvironment, including, but not limited, epithelial-to-mesenchymal transitions, fibrosis and adipogenesis. An exploration of cellular changes in the thymus at various stages of life, including mouse models of in-born errors of immunity and with single cell RNA sequencing, is revealing an expanding number of distinct cell types influencing thymus functions. The thymus microenvironment, established through interactions between immature and mature thymocytes with thymus epithelial cells (TEC), is well known. Less well appreciated are the contributions of neural crest cell-derived mesenchymal cells, endothelial cells, diverse hematopoietic cell populations, adipocytes, and fibroblasts in the thymic microenvironment. In the current review, we will explore the contributions of the many stromal cell types participating in the formation, expansion, and contraction of the thymus under normal and pathophysiological processes. Such information will better inform approaches for restoring thymus functionality, including thymus organoid technologies, beneficial when an individuals’ own tissue is congenitally, clinically, or accidentally rendered non-functional.
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Affiliation(s)
- Pratibha Bhalla
- Department of Immunology, The University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Dong-Ming Su
- Department of Microbiology, Immunology & Genetics, The University of North Texas Health Sciences Center, Fort Worth, TX, United States
| | - Nicolai S C van Oers
- Department of Immunology, The University of Texas Southwestern Medical Center, Dallas, TX, United States.,Department of Microbiology, The University of Texas Southwestern Medical Center, Dallas, TX, United States.,Department of Pediatrics, The University of Texas Southwestern Medical Center, Dallas, TX, United States
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14
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Martinez-Ruíz GU, Morales-Sánchez A, Bhandoola A. Transcriptional and epigenetic regulation in thymic epithelial cells. Immunol Rev 2022; 305:43-58. [PMID: 34750841 PMCID: PMC8766885 DOI: 10.1111/imr.13034] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 10/22/2021] [Accepted: 10/26/2021] [Indexed: 01/03/2023]
Abstract
The thymus is required for the development of both adaptive and innate-like T cell subsets. There is keen interest in manipulating thymic function for therapeutic purposes in circumstances of autoimmunity, immunodeficiency, and for purposes of immunotherapy. Within the thymus, thymic epithelial cells play essential roles in directing T cell development. Several transcription factors are known to be essential for thymic epithelial cell development and function, and a few transcription factors have been studied in considerable detail. However, the role of many other transcription factors is less well understood. Further, it is likely that roles exist for other transcription factors not yet known to be important in thymic epithelial cells. Recent progress in understanding of thymic epithelial cell heterogeneity has provided some new insight into transcriptional requirements in subtypes of thymic epithelial cells. However, it is unknown whether progenitors of thymic epithelial cells exist in the adult thymus, and consequently, developmental relationships linking putative precursors with differentiated cell types are poorly understood. While we do not presently possess a clear understanding of stage-specific requirements for transcription factors in thymic epithelial cells, new single-cell transcriptomic and epigenomic technologies should enable rapid progress in this field. Here, we review our current knowledge of transcription factors involved in the development, maintenance, and function of thymic epithelial cells, and the mechanisms by which they act.
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Affiliation(s)
- Gustavo Ulises Martinez-Ruíz
- T Cell Biology and Development Unit, Laboratory of Genome Integrity, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
- Research Division, Faculty of Medicine, National Autonomous University of Mexico, Mexico City, Mexico
- Children’s Hospital of Mexico Federico Gomez, Mexico City, Mexico
| | - Abigail Morales-Sánchez
- T Cell Biology and Development Unit, Laboratory of Genome Integrity, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
- Children’s Hospital of Mexico Federico Gomez, Mexico City, Mexico
| | - Avinash Bhandoola
- T Cell Biology and Development Unit, Laboratory of Genome Integrity, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
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15
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Rota IA, Handel AE, Maio S, Klein F, Dhalla F, Deadman ME, Cheuk S, Newman JA, Michaels YS, Zuklys S, Prevot N, Hublitz P, Charles PD, Gkazi AS, Adamopoulou E, Qasim W, Davies EG, Hanson I, Pagnamenta AT, Camps C, Dreau HM, White A, James K, Fischer R, Gileadi O, Taylor JC, Fulga T, Lagerholm BC, Anderson G, Sezgin E, Holländer GA. FOXN1 forms higher-order nuclear condensates displaced by mutations causing immunodeficiency. SCIENCE ADVANCES 2021; 7:eabj9247. [PMID: 34860543 PMCID: PMC8641933 DOI: 10.1126/sciadv.abj9247] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 10/15/2021] [Indexed: 05/04/2023]
Abstract
The transcription factor FOXN1 is a master regulator of thymic epithelial cell (TEC) development and function. Here, we demonstrate that FOXN1 expression is differentially regulated during organogenesis and participates in multimolecular nuclear condensates essential for the factor’s transcriptional activity. FOXN1’s C-terminal sequence regulates the diffusion velocity within these aggregates and modulates the binding to proximal gene regulatory regions. These dynamics are altered in a patient with a mutant FOXN1 that is modified in its C-terminal sequence. This mutant is transcriptionally inactive and acts as a dominant negative factor displacing wild-type FOXN1 from condensates and causing athymia and severe lymphopenia in heterozygotes. Expression of the mutated mouse ortholog selectively impairs mouse TEC differentiation, revealing a gene dose dependency for individual TEC subtypes. We have therefore identified the cause for a primary immunodeficiency disease and determined the mechanism by which this FOXN1 gain-of-function mutant mediates its dominant negative effect.
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Affiliation(s)
- Ioanna A. Rota
- Department of Paediatrics and the MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Adam E. Handel
- Department of Paediatrics and the MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Stefano Maio
- Department of Paediatrics and the MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Fabian Klein
- Department of Paediatrics and the MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Fatima Dhalla
- Department of Paediatrics and the MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Mary E. Deadman
- Department of Paediatrics and the MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Stanley Cheuk
- Department of Paediatrics and the MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Joseph A. Newman
- Structural Genomics Consortium, University of Oxford, ORCRB, Roosevelt Drive, Oxford, UK
| | - Yale S. Michaels
- Genome Engineering and Synthetic Biology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Saulius Zuklys
- Paediatric Immunology, Department of Biomedicine, University of Basel and University Children’s Hospital Basel, Basel, Switzerland
| | - Nicolas Prevot
- Department of Paediatrics and the MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Philip Hublitz
- MRC Weatherall Institute of Molecular Medicine, Genome engineering services, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Philip D. Charles
- Target Discovery Institute, University of Oxford, Oxford OX3 7FZ, UK
| | - Athina Soragia Gkazi
- Great Ormond Street Hospital and Great Ormond Street Institute of Child Health, University College London, London WC1N 1EH, UK
| | - Eleni Adamopoulou
- Department of Paediatrics and the MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Waseem Qasim
- Great Ormond Street Hospital and Great Ormond Street Institute of Child Health, University College London, London WC1N 1EH, UK
| | - Edward Graham Davies
- Great Ormond Street Hospital and Great Ormond Street Institute of Child Health, University College London, London WC1N 1EH, UK
| | - Imelda Hanson
- Department of Pediatrics, Section of Pediatric Immunology, Allergy, and Retrovirology, Baylor College of Medicine, Houston, TX, USA
| | - Alistair T. Pagnamenta
- National Institute for Health Research Biomedical Research Centre, Oxford, UK
- Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Carme Camps
- National Institute for Health Research Biomedical Research Centre, Oxford, UK
- Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Helene M. Dreau
- Department of Oncology, University of Oxford, Oxford OX3 7DQ, UK
| | - Andrea White
- Institute for Immunology and Immunotherapy, Medical School, University of Birmingham, Birmingham B15 2TT, UK
| | - Kieran James
- Institute for Immunology and Immunotherapy, Medical School, University of Birmingham, Birmingham B15 2TT, UK
| | - Roman Fischer
- Target Discovery Institute, University of Oxford, Oxford OX3 7FZ, UK
| | - Opher Gileadi
- Structural Genomics Consortium, University of Oxford, ORCRB, Roosevelt Drive, Oxford, UK
| | - Jenny C. Taylor
- National Institute for Health Research Biomedical Research Centre, Oxford, UK
- Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Tudor Fulga
- Genome Engineering and Synthetic Biology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - B. Christoffer Lagerholm
- Wolfson Imaging Centre Oxford, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Headley Way, Oxford OX3 9DS, UK
| | - Graham Anderson
- Institute for Immunology and Immunotherapy, Medical School, University of Birmingham, Birmingham B15 2TT, UK
| | - Erdinc Sezgin
- Paediatric Immunology, Department of Biomedicine, University of Basel and University Children’s Hospital Basel, Basel, Switzerland
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Georg A. Holländer
- Department of Paediatrics and the MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
- Paediatric Immunology, Department of Biomedicine, University of Basel and University Children’s Hospital Basel, Basel, Switzerland
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
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16
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Hu C, Zhang K, Jiang F, Wang H, Shao Q. Epigenetic modifications in thymic epithelial cells: an evolutionary perspective for thymus atrophy. Clin Epigenetics 2021; 13:210. [PMID: 34819170 PMCID: PMC8612001 DOI: 10.1186/s13148-021-01197-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 11/08/2021] [Indexed: 02/06/2023] Open
Abstract
Background The thymic microenvironment is mainly comprised of thymic epithelial cells, the cytokines, exosomes, surface molecules, and hormones from the cells, and plays a vital role in the development, differentiation, maturation and homeostasis of T lymphocytes. However, the thymus begins to degenerate as early as the second year of life and continues through aging in human beings, leading to a decreased output of naïve T cells, the limited TCR diversity and an expansion of monoclonal memory T cells in the periphery organs. These alternations will reduce the adaptive immune response to tumors and emerging infectious diseases, such as COVID-19, also it is easier to suffer from autoimmune diseases in older people. In the context of global aging, it is important to investigate and clarify the causes and mechanisms of thymus involution. Main body Epigenetics include histone modification, DNA methylation, non-coding RNA effects, and chromatin remodeling. In this review, we discuss how senescent thymic epithelial cells determine and control age-related thymic atrophy, how this process is altered by epigenetic modification. How the thymus adipose influences the dysfunctions of the thymic epithelial cells, and the prospects of targeting thymic epithelial cells for the treatment of thymus atrophy. Conclusion Epigenetic modifications are emerging as key regulators in governing the development and senescence of thymic epithelial cells. It is beneficial to re-establish effective thymopoiesis, identify the potential therapeutic strategy and rejuvenate the immune function in the elderly.
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Affiliation(s)
- Cexun Hu
- Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, People's Republic of China.,Department of Immunology, Key Laboratory of Medical Science and Laboratory Medicine of Jiangsu Province, School of Medicine, Jiangsu University, No. 301 Xuefu Road, Zhenjiang, 212013, Jiangsu, People's Republic of China
| | - Keyu Zhang
- Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, People's Republic of China.,Department of Immunology, Key Laboratory of Medical Science and Laboratory Medicine of Jiangsu Province, School of Medicine, Jiangsu University, No. 301 Xuefu Road, Zhenjiang, 212013, Jiangsu, People's Republic of China
| | - Feng Jiang
- Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, People's Republic of China.,Department of Immunology, Key Laboratory of Medical Science and Laboratory Medicine of Jiangsu Province, School of Medicine, Jiangsu University, No. 301 Xuefu Road, Zhenjiang, 212013, Jiangsu, People's Republic of China
| | - Hui Wang
- Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, People's Republic of China. .,Department of Immunology, Key Laboratory of Medical Science and Laboratory Medicine of Jiangsu Province, School of Medicine, Jiangsu University, No. 301 Xuefu Road, Zhenjiang, 212013, Jiangsu, People's Republic of China.
| | - Qixiang Shao
- Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, People's Republic of China. .,Department of Immunology, Key Laboratory of Medical Science and Laboratory Medicine of Jiangsu Province, School of Medicine, Jiangsu University, No. 301 Xuefu Road, Zhenjiang, 212013, Jiangsu, People's Republic of China. .,Jiangsu College of Nursing, School of Medical Science and Laboratory Medicine, Huai'an, 223002, Jiangsu, People's Republic of China.
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17
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ThymUS in times of stress. Nat Immunol 2021; 22:545-549. [PMID: 33692548 DOI: 10.1038/s41590-021-00897-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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18
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Collins C, Sharpe E, Silber A, Kulke S, Hsieh EWY. Congenital Athymia: Genetic Etiologies, Clinical Manifestations, Diagnosis, and Treatment. J Clin Immunol 2021; 41:881-895. [PMID: 33987750 PMCID: PMC8249278 DOI: 10.1007/s10875-021-01059-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 05/03/2021] [Indexed: 12/17/2022]
Abstract
Congenital athymia is an ultra-rare disease characterized by the absence of a functioning thymus. It is associated with several genetic and syndromic disorders including FOXN1 deficiency, 22q11.2 deletion, CHARGE Syndrome (Coloboma, Heart defects, Atresia of the nasal choanae, Retardation of growth and development, Genitourinary anomalies, and Ear anomalies), and Complete DiGeorge Syndrome. Congenital athymia can result from defects in genes that impact thymic organ development such as FOXN1 and PAX1 or from genes that are involved in development of the entire midline region, such as TBX1 within the 22q11.2 region, CHD7, and FOXI3. Patients with congenital athymia have profound immunodeficiency, increased susceptibility to infections, and frequently, autologous graft-versus-host disease (GVHD). Athymic patients often present with absent T cells but normal numbers of B cells and Natural Killer cells (T-B+NK+), similar to a phenotype of severe combined immunodeficiency (SCID); these patients may require additional steps to confirm the diagnosis if no known genetic cause of athymia is identified. However, distinguishing athymia from SCID is crucial, as treatments differ for these conditions. Cultured thymus tissue is being investigated as a treatment for congenital athymia. Here, we review what is known about the epidemiology, underlying etiologies, clinical manifestations, and treatments for congenital athymia.
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Affiliation(s)
- Cathleen Collins
- Department of Pediatrics, Division of Allergy Immunology, Rady Children's Hospital, University of California San Diego, San Diego, CA, USA
| | | | | | - Sarah Kulke
- Enzyvant Therapeutics, Inc, Cambridge, MA, USA
| | - Elena W Y Hsieh
- Department of Pediatrics, Section of Allergy and Immunology, Children's Hospital Colorado, University of Colorado School of Medicine, Aurora, CO, USA.
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO, USA.
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19
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Kreins AY, Bonfanti P, Davies EG. Current and Future Therapeutic Approaches for Thymic Stromal Cell Defects. Front Immunol 2021; 12:655354. [PMID: 33815417 PMCID: PMC8012524 DOI: 10.3389/fimmu.2021.655354] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 03/03/2021] [Indexed: 12/14/2022] Open
Abstract
Inborn errors of thymic stromal cell development and function lead to impaired T-cell development resulting in a susceptibility to opportunistic infections and autoimmunity. In their most severe form, congenital athymia, these disorders are life-threatening if left untreated. Athymia is rare and is typically associated with complete DiGeorge syndrome, which has multiple genetic and environmental etiologies. It is also found in rare cases of T-cell lymphopenia due to Nude SCID and Otofaciocervical Syndrome type 2, or in the context of genetically undefined defects. This group of disorders cannot be corrected by hematopoietic stem cell transplantation, but upon timely recognition as thymic defects, can successfully be treated by thymus transplantation using cultured postnatal thymic tissue with the generation of naïve T-cells showing a diverse repertoire. Mortality after this treatment usually occurs before immune reconstitution and is mainly associated with infections most often acquired pre-transplantation. In this review, we will discuss the current approaches to the diagnosis and management of thymic stromal cell defects, in particular those resulting in athymia. We will discuss the impact of the expanding implementation of newborn screening for T-cell lymphopenia, in combination with next generation sequencing, as well as the role of novel diagnostic tools distinguishing between hematopoietic and thymic stromal cell defects in facilitating the early consideration for thymus transplantation of an increasing number of patients and disorders. Immune reconstitution after the current treatment is usually incomplete with relatively common inflammatory and autoimmune complications, emphasizing the importance for improving strategies for thymus replacement therapy by optimizing the current use of postnatal thymus tissue and developing new approaches using engineered thymus tissue.
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Affiliation(s)
- Alexandra Y. Kreins
- Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
- Department of Immunology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom
| | - Paola Bonfanti
- Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
- Epithelial Stem Cell Biology & Regenerative Medicine Laboratory, The Francis Crick Institute, London, United Kingdom
- Institute of Immunity & Transplantation, University College London, London, United Kingdom
| | - E. Graham Davies
- Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
- Department of Immunology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom
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20
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Song J, Hoenerhoff M, Yang D, Yang Y, Deng C, Wen L, Ma L, Pallas B, Zhao C, Koike Y, Koike T, Lester P, Yang B, Zhang J, Chen YE, Xu J. Development of the Nude Rabbit Model. Stem Cell Reports 2021; 16:656-665. [PMID: 33606990 PMCID: PMC7940256 DOI: 10.1016/j.stemcr.2021.01.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 01/18/2021] [Accepted: 01/19/2021] [Indexed: 12/25/2022] Open
Abstract
Loss-of-function mutations in the forkhead box N1 (FOXN1) gene lead to nude severe combined immunodeficiency, a rare inherited syndrome characterized by athymia, severe T cell immunodeficiency, congenital alopecia, and nail dystrophy. We recently produced FOXN1 mutant nude rabbits (NuRabbits) by using CRISPR-Cas9. Here we report the establishment and maintenance of the NuRabbit colony. NuRabbits, like nude mice, are hairless, lack thymic development, and are immunodeficient. To demonstrate the functional applications of NuRabbits in biomedical research, we show that they can successfully serve as the recipient animals in xenotransplantation experiments using human induced pluripotent stem cells or tissue-engineered blood vessels. Our work presents the NuRabbit as a new member of the immunodeficient animal model family. The relatively large size and long lifespan of NuRabbits offer unique applications in regenerative medicine, cancer research, and the study of a variety of other human conditions, including immunodeficiency. NuRabbit colony is established and available for the research community NuRabbits are nude and immunodeficient due to a mutation(s) in the FOXN1 gene NuRabbits support iPSC teratoma assay NuRabbits support xenotransplant of tissue-engineered blood vessels
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Affiliation(s)
- Jun Song
- Center for Advanced Models and Translational Sciences and Therapeutics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Mark Hoenerhoff
- Unit for Laboratory Animal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Dongshan Yang
- Center for Advanced Models and Translational Sciences and Therapeutics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Ying Yang
- Department of Cardiac Surgery, University of Michigan School of Medicine, Ann Arbor, MI, USA
| | - Cheng Deng
- Department of Cardiac Surgery, University of Michigan School of Medicine, Ann Arbor, MI, USA
| | - Luan Wen
- Center for Advanced Models and Translational Sciences and Therapeutics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Linyuan Ma
- Center for Advanced Models and Translational Sciences and Therapeutics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Brooke Pallas
- Center for Advanced Models and Translational Sciences and Therapeutics, University of Michigan, Ann Arbor, MI 48109, USA; Unit for Laboratory Animal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Changzhi Zhao
- Center for Advanced Models and Translational Sciences and Therapeutics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Yui Koike
- Center for Advanced Models and Translational Sciences and Therapeutics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Tomonari Koike
- Center for Advanced Models and Translational Sciences and Therapeutics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Patrick Lester
- Unit for Laboratory Animal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Bo Yang
- Department of Cardiac Surgery, University of Michigan School of Medicine, Ann Arbor, MI, USA
| | - Jifeng Zhang
- Center for Advanced Models and Translational Sciences and Therapeutics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Y Eugene Chen
- Center for Advanced Models and Translational Sciences and Therapeutics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jie Xu
- Center for Advanced Models and Translational Sciences and Therapeutics, University of Michigan, Ann Arbor, MI 48109, USA.
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21
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Buchbinder D, Walter JE, Butte MJ, Chan WY, Chitty Lopez M, Dimitriades VR, Dorsey MJ, Nugent DJ, Puck JM, Singh J, Collins CA. When Screening for Severe Combined Immunodeficiency (SCID) with T Cell Receptor Excision Circles Is Not SCID: a Case-Based Review. J Clin Immunol 2021; 41:294-302. [PMID: 33411155 PMCID: PMC8179373 DOI: 10.1007/s10875-020-00931-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 11/18/2020] [Indexed: 12/19/2022]
Abstract
Newborn screening efforts focusing on the quantification of T cell receptor excision circles (TRECs), as a biomarker for abnormal thymic production of T cells, have allowed for the identification and definitive treatment of severe combined immunodeficiency (SCID) in asymptomatic neonates. With the adoption of TREC quantification in Guthrie cards across the USA and abroad, typical, and atypical SCID constitutes only ~ 10% of cases identified with abnormal TRECs associated with T cell lymphopenia. Several other non-SCID-related conditions may be identified by newborn screening in a term infant. Thus, it is important for physicians to recognize that other factors, such as prematurity, are often associated with low TRECs initially, but often improve with age. This paper focuses on a challenge that immunologists face: the diagnostic evaluation and management of cases in which abnormal TRECs are associated with variants of T cell lymphopenia in the absence of a genetically defined form of typical or atypical SCID. Various syndromes associated with T cell impairment, secondary forms of T cell lymphopenia, and idiopathic T cell lymphopenia are identified using this screening approach. Yet there is no consensus or guidelines to assist in the evaluation and management of these newborns, despite representing 90% of the patients identified, resulting in significant work for the clinical teams until a diagnosis is made. Using a case-based approach, we review pearls relevant to the evaluation of these newborns, as well as the management dilemmas for the families and team related to the resolution of genetic ambiguities.
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Affiliation(s)
- David Buchbinder
- Department of Hematology, Children's Hospital of Orange County, Orange, CA, USA.
- Department of Pediatrics, University of California at Irvine, Orange, CA, USA.
| | - Jolan E Walter
- Division of Pediatric, University of South Florida at Johns Hopkins All Children's Hospital, Allergy/ Immunology, St. Petersburg, FL, USA
- Division of Pediatric Allergy and Immunology, Massachusetts General Hospital for Children, Boston, MA, USA
| | - Manish J Butte
- Division of Immunology, Allergy, and Rheumatology, Department of Pediatrics, University of California Los Angeles, Los Angeles, CA, USA
| | - Wan-Yin Chan
- Department of Allergy & Immunology, Children's Hospital of Orange County, Orange, CA, USA
| | - Maria Chitty Lopez
- Division of Pediatric, University of South Florida at Johns Hopkins All Children's Hospital, Allergy/ Immunology, St. Petersburg, FL, USA
| | - Victoria R Dimitriades
- Division of Allergy, Immunology & Rheumatology, Department of Pediatrics, Sacramento, CA, USA
| | - Morna J Dorsey
- Department of Allergy & Immunology, University of California, San Francisco, CA, USA
| | - Diane J Nugent
- Department of Hematology, Children's Hospital of Orange County, Orange, CA, USA
- Department of Pediatrics, University of California at Irvine, Orange, CA, USA
| | - Jennifer M Puck
- Department of Allergy & Immunology, University of California, San Francisco, CA, USA
| | - Jasjit Singh
- Department of Infectious Disease, Children's Hospital of Orange County, Orange, CA, USA
| | - Cathleen A Collins
- Department of Pediatrics, Division of Allergy Immunology, University of California at San Diego, La Jolla, CA, USA
- Department of Pediatrics, Division of Allergy Immunology, Rady Children's Hospital, San Diego, CA, USA
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22
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Currier R, Puck JM. SCID newborn screening: What we've learned. J Allergy Clin Immunol 2021; 147:417-426. [PMID: 33551023 PMCID: PMC7874439 DOI: 10.1016/j.jaci.2020.10.020] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 10/15/2020] [Accepted: 10/19/2020] [Indexed: 12/15/2022]
Abstract
Newborn screening for severe combined immunodeficiency, the most profound form of primary immune system defects, has long been recognized as a measure that would decrease morbidity and improve outcomes by helping patients avoid devastating infections and receive prompt immune-restoring therapy. The T-cell receptor excision circle test, developed in 2005, proved to be successful in pilot studies starting in the period 2008 to 2010, and by 2019 all states in the United States had adopted versions of it in their public health programs. Introduction of newborn screening for severe combined immunodeficiency, the first immune disorder accepted for population-based screening, has drastically changed the presentation of this disorder while providing important lessons for public health programs, immunologists, and transplanters.
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Affiliation(s)
- Robert Currier
- Division of Allergy, Immunology and Blood and Marrow Transplantation, Department of Pediatrics, University of California San Francisco School of Medicine and UCSF Benioff Children's Hospital San Francisco, San Francisco, Calif
| | - Jennifer M Puck
- Division of Allergy, Immunology and Blood and Marrow Transplantation, Department of Pediatrics, University of California San Francisco School of Medicine and UCSF Benioff Children's Hospital San Francisco, San Francisco, Calif.
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23
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Expanding the Nude SCID/CID Phenotype Associated with FOXN1 Homozygous, Compound Heterozygous, or Heterozygous Mutations. J Clin Immunol 2021; 41:756-768. [PMID: 33464451 PMCID: PMC8068652 DOI: 10.1007/s10875-021-00967-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 01/06/2021] [Indexed: 12/11/2022]
Abstract
Human nude SCID is a rare autosomal recessive inborn error of immunity (IEI) characterized by congenital athymia, alopecia, and nail dystrophy. Few cases have been reported to date. However, the recent introduction of newborn screening for IEIs and high-throughput sequencing has led to the identification of novel and atypical cases. Moreover, immunological alterations have been recently described in patients carrying heterozygous mutations. The aim of this paper is to describe the extended phenotype associated with FOXN1 homozygous, compound heterozygous, or heterozygous mutations. We collected clinical and laboratory information of a cohort of 11 homozygous, 2 compound heterozygous, and 5 heterozygous patients with recurrent severe infections. All, except one heterozygous patient, had signs of CID or SCID. Nail dystrophy and alopecia, that represent the hallmarks of the syndrome, were not always present, while almost 50% of the patients developed Omenn syndrome. One patient with hypomorphic compound heterozygous mutations had a late-onset atypical phenotype. A SCID-like phenotype was observed in 4 heterozygous patients coming from the same family. A spectrum of clinical manifestations may be associated with different mutations. The severity of the clinical phenotype likely depends on the amount of residual activity of the gene product, as previously observed for other SCID-related genes. The severity of the manifestations in this heterozygous family may suggest a mechanism of negative dominance of the specific mutation or the presence of additional mutations in noncoding regions.
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24
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Thorsen J, Kolbert K, Joshi A, Baker M, Seroogy CM. Newborn Screening for Severe Combined Immunodeficiency: 10-Year Experience at a Single Referral Center (2009-2018). J Clin Immunol 2021; 41:595-602. [PMID: 33409868 DOI: 10.1007/s10875-020-00956-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 12/23/2020] [Indexed: 12/18/2022]
Abstract
In 2008, newborn screening (NBS) for severe combined immunodeficiency (SCID) began as a pilot study in Wisconsin and has recently been added to every state's newborn screen panel. The incidence of SCID is estimated at 1 per 58,000 births which may suggest infrequent NBS SCID screen positive results in states with low annual birth rates. In this study, we report our center's experience with NBS positive SCID screen referrals over a 10-year period. A total of 68 full-term newborns were referred to our center for confirmatory testing. Of these referrals, 50% were false positives, 12% were SCID diagnoses, 20% syndromic T cell lymphopenia (TCL) disorders, and 18% non-SCID, non-syndromic TCL. Through collaboration with our newborn screening lab, second-tier targeted gene sequencing was performed for newborns with SCID screen positive results from communities with known founder pathogenic variants and provided rapid genetic confirmation of SCID and non-SCID TCL disorders. Despite extensive genetic testing, two of the eight (25%) identified newborns with SCID diagnoses lacked a definable genetic defect. Additionally, our referrals included ten newborns who were otherwise healthy newborns with idiopathic TCL and varied CD3+ T cell number longitudinal trajectories. Collectively, referrals to our single site over a 10-year period describe a broad spectrum of medically actionable and idiopathic TCL disorders which highlight the importance of clinical immunology expertise in all states, demonstrate efficiencies and challenges for second-tier genetic testing, and further emphasize the need to development standardized evaluation algorithms for non-SCID TCL.
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Affiliation(s)
- Julia Thorsen
- Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, 1111 Highland Avenue, 4139 WIMR, Madison, WI, 53705-2275, USA
| | - Kayla Kolbert
- Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, 1111 Highland Avenue, 4139 WIMR, Madison, WI, 53705-2275, USA
| | - Avni Joshi
- Division of Allergy and Immunology, Mayo Clinic Children's Center, Rochester, MN, USA
| | - Mei Baker
- Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, 1111 Highland Avenue, 4139 WIMR, Madison, WI, 53705-2275, USA
- Wisconsin State Laboratory of Hygiene, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Christine M Seroogy
- Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, 1111 Highland Avenue, 4139 WIMR, Madison, WI, 53705-2275, USA.
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25
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Kreins AY, Maio S, Dhalla F. Inborn errors of thymic stromal cell development and function. Semin Immunopathol 2020; 43:85-100. [PMID: 33257998 PMCID: PMC7925491 DOI: 10.1007/s00281-020-00826-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 11/09/2020] [Indexed: 12/31/2022]
Abstract
As the primary site for T cell development, the thymus is responsible for the production and selection of a functional, yet self-tolerant T cell repertoire. This critically depends on thymic stromal cells, derived from the pharyngeal apparatus during embryogenesis. Thymic epithelial cells, mesenchymal and vascular elements together form the unique and highly specialised microenvironment required to support all aspects of thymopoiesis and T cell central tolerance induction. Although rare, inborn errors of thymic stromal cells constitute a clinically important group of conditions because their immunological consequences, which include autoimmune disease and T cell immunodeficiency, can be life-threatening if unrecognised and untreated. In this review, we describe the molecular and environmental aetiologies of the thymic stromal cell defects known to cause disease in humans, placing particular emphasis on those with a propensity to cause thymic hypoplasia or aplasia and consequently severe congenital immunodeficiency. We discuss the principles underpinning their diagnosis and management, including the use of novel tools to aid in their identification and strategies for curative treatment, principally transplantation of allogeneic thymus tissue.
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Affiliation(s)
- Alexandra Y Kreins
- UCL Great Ormond Street Institute of Child Health, London, UK.,Department of Immunology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Stefano Maio
- Developmental Immunology, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Fatima Dhalla
- Developmental Immunology, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK. .,Department of Clinical Immunology, Oxford University Hospitals, Oxford, UK.
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26
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Castagnoli R, Notarangelo LD. Updates on new monogenic inborn errors of immunity. Pediatr Allergy Immunol 2020; 31 Suppl 26:57-59. [PMID: 33236415 PMCID: PMC8322961 DOI: 10.1111/pai.13365] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 08/05/2020] [Indexed: 12/31/2022]
Abstract
Inborn errors of immunity (IEI), also referred to as primary immunodeficiencies (PID), are disorders that, for the most part, result from mutations in genes involved in immune host defense and immune regulation. Thanks to the increased availability of high-throughput DNA sequencing and the improvement in genomic data interpretation, the number of newly identified genes associated with IEI has exponentially increased over the last decade. We reviewed four recently described monogenic IEI and discussed the clinical and immunologic features of these new conditions.
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Affiliation(s)
- Riccardo Castagnoli
- Laboratory of Clinical Immunology and Microbiology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.,Pediatric Clinic, Fondazione IRCCS Policlinico San Matteo, University of Pavia, Pavia, Italy.,Department of Clinical, Surgical, Diagnostic and Pediatric Sciences, University of Pavia, Pavia, Italy.,Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Luigi Daniele Notarangelo
- Laboratory of Clinical Immunology and Microbiology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
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27
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Abstract
PURPOSE OF REVIEW Transplantation of cultured postnatal allogeneic thymus has been successful for treating athymia, mostly associated with complete DiGeorge syndrome, for more than 20 years. Advances in molecular genetics provide opportunities for widening the range of athymic conditions that can be treated while advances in cell culture and organ/tissue regeneration may offer the prospect of alternative preparations of thymic tissue. There are potential broader applications of this treatment outside congenital athymia. RECENT FINDINGS At the same time as further characterization of the cultured thymus product in terms of thymic epithelial cells and lymphoid composition, preclinical studies have looked at de-novo generation of thymic epithelial cells from stem cells and explored scaffolds for delivering these as three-dimensional structures. In the era of newborn screening for T-cell lymphopaenia, a broadening range of defects leading to athymia is being recognized and new assays should allow differentiation of these from haematopoietic cell defects, pending their genetic/molecular characterization. Evidence suggests that the tolerogenic effect of transplanted thymus could be exploited to improve outcomes after solid organ transplantation. SUMMARY Thymus transplantation, the accepted standard treatment for complete DiGeorge syndrome is also appropriate for other genetic defects leading to athymia. Improved strategies for generating thymus may lead to better outcomes and broader application of this treatment.
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28
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Bhalla P, Wysocki CA, van Oers NSC. Molecular Insights Into the Causes of Human Thymic Hypoplasia With Animal Models. Front Immunol 2020; 11:830. [PMID: 32431714 PMCID: PMC7214791 DOI: 10.3389/fimmu.2020.00830] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 04/14/2020] [Indexed: 12/30/2022] Open
Abstract
22q11.2 deletion syndrome (DiGeorge), CHARGE syndrome, Nude/SCID and otofaciocervical syndrome type 2 (OTFCS2) are distinct clinical conditions in humans that can result in hypoplasia and occasionally, aplasia of the thymus. Thymic hypoplasia/aplasia is first suggested by absence or significantly reduced numbers of recent thymic emigrants, revealed in standard-of-care newborn screens for T cell receptor excision circles (TRECs). Subsequent clinical assessments will often indicate whether genetic mutations are causal to the low T cell output from the thymus. However, the molecular mechanisms leading to the thymic hypoplasia/aplasia in diverse human syndromes are not fully understood, partly because the problems of the thymus originate during embryogenesis. Rodent and Zebrafish models of these clinical syndromes have been used to better define the underlying basis of the clinical presentations. Results from these animal models are uncovering contributions of different cell types in the specification, differentiation, and expansion of the thymus. Cell populations such as epithelial cells, mesenchymal cells, endothelial cells, and thymocytes are variably affected depending on the human syndrome responsible for the thymic hypoplasia. In the current review, findings from the diverse animal models will be described in relation to the clinical phenotypes. Importantly, these results are suggesting new strategies for regenerating thymic tissue in patients with distinct congenital disorders.
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Affiliation(s)
- Pratibha Bhalla
- Department of Immunology, The University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Christian A Wysocki
- Department of Pediatrics, The University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Nicolai S C van Oers
- Department of Immunology, The University of Texas Southwestern Medical Center, Dallas, TX, United States.,Department of Pediatrics, The University of Texas Southwestern Medical Center, Dallas, TX, United States.,Department of Microbiology, The University of Texas Southwestern Medical Center, Dallas, TX, United States
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29
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Differentiation of human pluripotent stem cells toward pharyngeal endoderm derivatives: Current status and potential. Curr Top Dev Biol 2020; 138:175-208. [PMID: 32220297 DOI: 10.1016/bs.ctdb.2020.01.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
The pharyngeal apparatus, a transient embryological structure, includes diverse cells from all three germ layers that ultimately contribute to a variety of adult tissues. In particular, pharyngeal endoderm produces cells of the inner ear, palatine tonsils, the thymus, parathyroid and thyroid glands, and ultimobranchial bodies. Each of these structures and organs contribute to vital human physiological processes, including central immune tolerance (thymus) and metabolic homeostasis (parathyroid and thyroid glands, and ultimobranchial bodies). Thus, improper development or damage to pharyngeal endoderm derivatives leads to complicated and severe human maladies, such as autoimmunity, immunodeficiency, hypothyroidism, and/or hypoparathyroidism. To study and treat such diseases, we can utilize human pluripotent stem cells (hPSCs), which differentiate into functionally mature cells in vitro given the proper developmental signals. Here, we discuss current efforts regarding the directed differentiation of hPSCs toward pharyngeal endoderm derivatives. We further discuss model system and therapeutic applications of pharyngeal endoderm cell types produced from hPSCs. Finally, we provide suggestions for improving hPSC differentiation approaches to pharyngeal endoderm derivatives with emphasis on current single cell-omics and 3D culture system technologies.
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